include <bits/stdc++.h>
define endl '\n'
using namespace std;
typedef long long ll;
typedef pair<char,char> pll;
unordered_map<char,pll> mp;
void fid(char pos){
char l=mp[pos].first,r=mp[pos].second;
cout<<pos;
if(l!='')fid(l);
if(r!='')fid(r);
}
int main(){
ios::sync_with_stdio(false);cin.tie(0);
ll n;
cin>>n;
char root;
for(ll i=0;i<n;i++){
char a,b,c;
cin>>a>>b>>c;
if(i==0)root=a;
mp[a]={b,c};
}
fid(root);
cout<<endl;
return 0;
}